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Transmission whine

14K views 22 replies 6 participants last post by  silent35 
#1 ·
I have a 97 Grand Cherokee Limited 5.2L with a 42RE Transmission. So with a little explanation, I have a whine coming from the transmission near the bell housing. When this whine occurs the trans will quit pulling in any gear. I can turn off the ignition, re-start and pull back into gear and all is well for somewhere between 30 feet and 3 miles depending on the mood of the trans. It will eventually quit pulling all together. So after 5 used transmissions, removal of the check valve in the return line, 1 new complete solenoid kit with regulator, and sensors, a new torque convertor, a new pcm, completely ohmed trans wires and a new transmission relay, none of these actually helped anything, I can only get the transmission to last about a month then I have to replace it again. I have bought all the 42re's in my area now so I can't get anymore used. I honestly don't think the issue is with the trans but I cant be sure. I don't want to pay for a rebuild and have it fail in a month. Any ideas on what the cause may be. It sounds like a power steering pump low on fluid. I used ATF 4 synthetic fluid with new filters and seals on every transmission.
 
#3 ·
I see I am getting several views but no replies so I must be the only one with this problem or more likely I am not the only one confused by this problem which does make me feel better. Not helping my wife's mood though since it is her everyday driver. Looks like I failed to mention that I also replaced the radiator and the auxiliary trans cooler out front as well. One weird thing though is that I had to replace the radiator due to the trans cooler in it breaking and putting coolant into my transmission. This happened after removal of the check valve in the return line so I wonder what could have caused the pressure to spike high enough to break the cooler, or was it just a bad radiator that was time to go.
 
#4 ·
You might want to check the thermastat if stuck closed it will cause a spike in temperature and thus causing the tranny to overheat.
Anytime a rad.is changed you should change the thermastat.
Have you pulled the plan to see if there is coolent in the tanny fluid? If no coolent in the tranny fluid were the lines flushed when the tranny was replaced? Coolent and clutch plates don't get along.
 
#6 ·
exmilitary, the Jeep has never overheated but yes there was coolant in the trans fluid. This happened on the 5th transmission when the cooler broke. I flushed the system and replaced the filter and fluid. I actually didn't have the transmission issue at that point but it showed up a month later, however the other 4 transmissions did the same whine and no pull prior to the break in the trans mission cooler.
98ZJOKC, The only gear it does not whine in is park and yes the sound increases tempo with engine rpm's also increasing in loudness when the no pull occurs. When it quits pulling I shut off the engine immediately restart the engine pull the trans in gear and go some more but the whine is still there even then just not as prominent.
 
#9 ·
Fluid level dead on the full mark with no leaks ATF 4 synthetic. Also hauled the Jeep to a "transmission mechanic" and had the thing scanned. Don't remember the exact code but it was something to the effect of torque converter speed does not match engine rpm which was obvious since it wouldn't pull this from the same person who told me there was no pressure regulator or sensor in the trans even after I told him it was cause I had already replaced them once. That was the only code in it.
 
#10 ·
My wife thinks it is wiring pre PCM. I know this is a statement that will raise some eyebrows. She is sighting the fact that I already checked all the wires to the trans and replaced the PCM. She is sighting other issues in the past such as, headlights rapidly flashing off and on with a relay sound under the dash which has happened once while going down the road, this was kinda cool since every car we meet immediately pulled off the side of the road, also the VIC shorted and drained the battery till I unplugged it, the driver side mirror is stuck on dim feature, the overdrive switch kicked on by itself and wouldn't turn off for several days then went off by itself but this only happened once and on one of the previous transmissions, the transmission was stuck in low one time but I found that to be the kickdown lever covered in ice during an ice storm, car wash fixed that.
 
#12 ·
Just came in from checking. It doesn't touch the engine and is almost perfectly straight to the mount on the transmission. No kinks or anything like that and the only place I see it touch the trans is at the mount and linkage. I couldn't see any better way to route it either.
 
#13 ·
I bought a used transmission with a new overdrive unit in it yesterday. Can't put it in today but I will tomorrow. If I don't find the issue this time the only thing I know to do is trade it off and I really hate to do that. Does the BCM have any control what so ever for the transmission or even a part of the PCM associated with the trans?
 
#14 ·
I am stuck with the thought that I have a pressure issue. Blowing the cooler seems to be over pressure and happened with no whine occurring. The whine seems to be an under pressure/air type of sound. I believe the pump and torque converter build pressure and they seem fine. The lines are clear. the coolers are new. Would an after market filter cause any of these issues? I have used the same brand filter on every transmission so far and really don't think it is the issue but it is one of the parts that is common with every transmission so far. What would the pressure on the return line be and in what gear and what rpm.
 
#17 ·
I unhooked the cable and put the transmission in neutral from underneath, still had the whine so I put it in drive and reverse from underneath still had the whine and no pull now. Guess its completely out now but that should eliminate the adjustment problem or would it?
 
#21 ·
update, talked to another transmission mechanic locally who comes highly recommended. He told me to replace the auxiliary cooler with one that has bigger cores and don't use the radiator cooler. Went home and routed the lines straight out and back into the transmission with a 12 inch long hose. Still whine with no pull. Replaced the transmission with another used one that I bought that has a new OD unit on it. Put new lines on and went straight to a new large core cooler out front and skipped everything else with the lines. No whine and perfect pull and shift so I guess we'll see what happens. I'll try to update in a month or so. Thanks for all the help and ZeeJay the schematic and troubleshooting gave me several ideas, I really appreciate it.
 
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